1. Field of the Invention
This invention relates to printers, and in particular it is concerned with a multicolor printer suitable for use in printing record data in colors conforming to color designating data.
2. Description of the Prior Art
Printers of an electrographic printing system and a thermographic printing system are known in the art for printing record data in colors conforming to color designating data by using the primary colors of cyan, yellow and magenta either singly or by subtractive color mixing. Of these two types of multicolor printers, the printer of the electrographic printing system has a multiplicity of electrodes spaced apart from each other by a spacing interval conforming to a predetermined resolution and selectively actuated to discharge in accordance with the record data of each one of the three primary colors so as to charge an insulating material layer of a conductive member to form an electrostatic latent image thereon. A toner of one color is electrostatically caused to adhere to the electrostatic latent image thus formed to develop the same into a toner image which is then printed by transferprinting on a sheet of support material. This process is repeated three times to effect subtractive color mixing of the toners of three different colors, so as to print the record data in multicolor in accordance with color designating data by using the three primary colors either singly or by subtractive color mixing. In the multicolor printer of the thermographic printing system, a thermal head is driven based on record data for each one of the three primary colors to successively effect thermal-transfer of an ink of each one of the three primary colors to a sheet of support material. As the thermal transfer of the inks of the three primary colors has been effected, record data is printed in multicolor in accordance with color designating data by using the three primary colors either singly or by subtractive color mixing.
Some disadvantages are associated with the multicolor printers of the aforesaid constructions of the prior art. In the multicolor printer of the electrographic printing system, it is necessary that the electrostatic latent image forming step and electrostatic latent image developing step be performed three times for each of the three primary colors. This has prolonged the period of time required for performing a multicolor printing operation and rendered the construction of the printer complex. In the multicolor printer of the thermographic printing system, it is also necessary that the thermal transfer-printing step be performed three times for each of the three primary colors. This not only prolongs the period of time required for performing a printing operation but also makes it necessary to feed a sheet of support material for each one of the three primary colors to print record data in multicolor. The sheet of support material shows changes in properties depending on the manner in which it is fed and the manner in which inks are thermally transferred thereto. Thus, great difficulties are experienced in positively performing subtractive color mixing of the three primary colors of cyan, yellow and magenta in conformity with a predetermined resolution. As a result, printouts of record data are generally low in quality due to mismatching of the three primary colors.